1.50

Changes:

• implement better algorithm for jetway selection
• provide ui for manual selection of jw to door
• improve precision of jw docking
• use staggered start for dock/undock with multiple doors so jetways don't collide
• for ToLiss A321 extract door config from livery
• support marshaller on stairs
• Safegate must be turned by 180° for SAM1 + SAM2
• augment XP12's 'sim/ground_ops/jetway' command to toggle SAM jetways
• various tweaks and stability fixes